The document ISO/IEC 13818-2 relates to the MPEG-2 standard. Section 7 describes decoding steps for deriving a sequence of pictures from a data stream. These decoding steps include, amongst others, variable-length decoding, inverse quantization, inverse discrete-cosine transformation, and motion compensation. A sequence of pictures is coded in accordance with the MPEG-2 standard if a data stream is obtained which, by applying the decoding steps described in section 7, results in a correctly decoded sequence of pictures.